Based on the thread starter's feedback, the best way to go forward is through a virtual assistant.
The problem with simply advertising that you have a guest post for sale on your blog or website for all the general public to see is that you are taking a risk of getting penalized sooner than later.
Also, you are taking the risk of attracting linked builders that may not be in your niche.
If you post enough unrelated links, your website will be penalized.
It is much better to hire a virtual assistant to find a niche- related brands and approach them through social media, whether they would be interested in a win-win situation with you.
There are many ways to phrase paid guest post.
You don't have to be brutally frank and upfront about it because it would come off like you are selling links.
Hopefully, you can see what is wrong with that situation.
The key here is an outreach to niche- targeted direct advertisers or agencies that handle specific niches.